Floppy Trunk Syndrome

Floppy Trunk Syndrome is also known as flaccid trunk paralysis. It is a condition that causes trunk paralysis in African bush elephants (Loxodonta africana). Initially observed in 1989, the syndrome primarily affected bull elephants in several select regions in Zimbabwe[1].

The paralysis has been observed to start at the tip and work its way upward over the course of several months. As their trunks become increasingly paralyzed, elephants have difficulty feeding and learn to use their front feet or throw their trunk over branches to aid feeding. To avoid stomping on their trunk while walking, an elephant afflicted with the condition would fling their trunk over their tusks. In later stages of paralysis, affected elephants needed to submerge themselves partially in water to drink. However, despite these learned adaptations, affected elephants were observed as emaciated, suffering from muscle atrophy and a lack of visceral fat. Untreated, this handicap could result in starvation.

The syndrome has only been observed in free-ranging elephants, specifically African bush elephants and primarily affects older male elephants. Over thirty elephants were observed to be afflicted with this paralysis.

The cause of this syndrome is currently unknown, but researchers suggest several possible poisonous plant species, such as Heliotropium ovalifolium, Indigofera and Boerhavia. Cases of poisoning of sheep and goat in Sudan have been reported, and a fatal liver disease in Australian horses has been attributed to Heliotropium ovalifolium. However, extensive tests using extracts of the plant failed to reveal any neurotoxicity in in vivo test systems[2].

[1] Kock et al: Flaccid trunk paralysis in free-ranging elephants (Loxodonta africana) in Zimbabwe in Journal of Wildlife Diseases – 1994
[2] Guntern et al: Heliotropamide, a Novel Oxopyrrolidine-3-carboxamide from Heliotropium ovalifolium in Journal of Natural Products – 2003